I have used a couple different approaches. User Documentation has been done on a Notes Dashboard and Developer documentation done in the Document Scripts as comment section. I often keep history of technical changes in the Document Scripts
I have also written documentation on the file and printed that file to PDF then put a link on the Dashboard to the document whether it is hosted on the EPM Server as static content or a document library maybe hosted on a portal like SharePoint. This approach is often good if you are using Use Cases, Design Docs, etc and want them available
You gave some approaches that I did not think about. Thank You very much.